Different conclusions can be drawn from the image data of various, known medical examination devices. Whilst X-ray based image data provide statements of the attenuation coefficients of the displayed object under examination, knowledge of the proton density or density of the respective, excited nuclei, relaxation parameters and other variables, can be obtained by means of magnetic resonance tomography. On the other hand, positron emission tomography (PET) enables functional imaging to be achieved without the resolution of magnetic resonance tomography, for example.
There is therefore a need for combined medical examination devices which ultimately permit the recording of image data of a plurality of examination devices, in order to achieve amalgamated image data. In particular, better data can then be derived for the diagnosis from this amalgamated image data than if only singular image data are examined, that is to say image data from a single examination device.
At the same time it is desirable to construct the examination devices so as to be spatially uniform in each case. Different examinations, for example magnetic resonance examinations and PET examinations can then be carried out on the patient simultaneously and therefore with a time saving. On the other hand, the recording of image data is extremely simple with this configuration of combined medical examination devices since, due to the simultaneity of the recordings, no movements of the patient have to be corrected and therefore a single calibration of the examination devices together before initial start-up makes subsequent amalgamation of the image data perfectly possible.
A problem of such types of combined devices is in the arrangement of the individual elements. In particular, devices inside the detection units must meet different and partially conflicting requirements for the respective examination devices. For example, to be suitable for magnetic resonance devices, patient positioning couches must not contain any ferromagnetic elements. There is no such requirement for positron emission tomography devices, but in this case the material must attenuate radiation only to a small extent.
It is therefore known for patient positioning couches for combined medical examination devices to be designed in such a way that, in the context of material research, a material is selected that best meets the requirements of the respective medical examination devices.